Scientists explore negative ions' dancing patterns

A team of Swedish and German researchers has uncovered how negative ions interact, according to findings set out in the Review of Scientific Instruments. Negative ions play a crucial role in everything from how our bodies function to how the universe is structured.

These results are important for our knowledge of superconductors and radiocarbon dating, as one of the study authors, Anton Lindahl, from the Department of Physics at the University of Gothenburg, explains: 'By studying atoms with a negative charge, "negative ions", we can learn how electrons coordinate their motion in what can be compared to a tightly choreographed dance. Such knowledge is important in understanding phenomena in which the interaction between electrons is important, such as in superconductors.'

A negative ion is an atom that has captured an extra electron, giving it a negative charge; an example of how they are formed is when salt dissolves in water. In our bodies there are many different types of ions, but the most common is chloride ions. These are important for cell fluid balance and nervous system functioning.

Knowing more about these negative ions could help us better understand where we came from; they play an important role in the chemical reactions that take place in space, being highly significant in processes like the formation of molecules from free atoms. These molecules may have been important building blocks in the origin of life.

Anton Lindahl continues: 'I have worked with ions in a vacuum, not in water as in the body. In order to be able to study the properties of individual ions, we isolate them in a vacuum chamber at extremely low pressure. This pressure is even lower than the pressure outside of the International Space Station, ISS. In order to be able to carry out these studies, I have had to develop measurement methods and build experimental equipment. The measurements that the new equipment makes possible will increase our understanding of the dance-like interplay.'

The new measurement methods that Mr Lindahl has developed can play an important role in a number of applications. One example is the measurement of trace substances in a technique known as accelerator mass spectrometry (AMS). AMS is applied in radiocarbon dating, which determines the age of organic matter. Another application of AMS is for measurements on ice cores drilled from polar ice, which can be used to investigate what our climate was like thousands of years ago.